For data transmission in packet form, the DAB (digital audio broadcasting) standard, for example, specifies a method for how data is to be transmitted in packet mode. This provides a method for error recognition to recognize incorrectly transmitted data packets (CRC method). Since the individual packets may be assembled into data groups and further into data files, a single incorrect bit may corrupt the transmission of large quantities of data. In DAB, error protection is achieved via a convolutional code. The goal in this case is to achieve a bit error rate of 10−4. However, practical experience has shown that while this bit error rate is sufficiently low for audio, it is too high for transmitting data services.
In the DVB-T method, a chained code of convolutional code and block code is used. Very low bit error rates, in the order of magnitude of 10−8, may be achieved in this way.